It looks that means the Lao people.

▲ 《大南一統志》, 卷之八

Note that 縣 here means 宣化縣 (Huyện Tuyên Hóa) in 廣平省 (Tỉnh Quảng Bình). ～𱏣 means Laotian, which was called as 哀牢蠻 or 哀牢夷 or 愛獠 in the ancient books. (cf. 哀牢山 in Chinese Yunnan Province) China called Laos as 老挝 since 1954 (http://finance.china.com.cn/roll/20150720/3241362.shtml) in Chinese mainland, but 寮國 is kept using in Taiwan Province.

Eiso is correct: is one way to write Lao, Laos, Laotian, etc. However, it's also used to write other words like "lào xào" (whisper, rustle). Note that the preferred modern form for Lào is 𠈭 (U+2022D) http://www.hannom-rcv.org/NS/bchnctd%20150123.pdf